Methods of cleaning a polycrystalline diamond body and methods of forming polycrystalline diamond compacts

ABSTRACT

Embodiments of the invention relate to methods of cleaning a leaching agent and/or leaching agent by-products from an at least partially leached polycrystalline diamond body, and methods of making a polycrystalline diamond compact using the same.

BACKGROUND

Wear-resistant, superabrasive compacts are utilized in a variety ofmechanical applications. For example, polycrystalline diamond compacts(“PDCs”) are used in drilling tools (e.g., cutting elements, gagetrimmers, etc.), machining equipment, bearing apparatuses, wire-drawingmachinery, and in other mechanical apparatuses.

PDCs have found particular utility as superabrasive cutting elements inrotary drill bits, such as roller cone drill bits and fixed cutter drillbits. A PDC cutting element typically includes a superabrasive diamondlayer (also known as a diamond table). The diamond table is formed andbonded to a substrate using an ultra-high pressure, ultra-hightemperature (“HPHT”) process. The PDC cutting element may also be brazeddirectly into a preformed pocket, socket, or other receptacle formed inthe bit body. The substrate may be often brazed or otherwise joined toan attachment member, such as a cylindrical backing. A rotary drill bittypically includes a number of PDC cutting elements affixed to the bitbody. It is also known that a stud carrying the PDC may be used as a PDCcutting element when mounted to a bit body of a rotary drill bit bypress-fitting, brazing, or otherwise securing the stud into a receptacleformed in the bit body.

Conventional PDCs are normally fabricated by placing a cemented-carbidesubstrate into a container or cartridge with a volume of diamondparticles positioned adjacent to a surface of the cemented-carbidesubstrate. A number of such cartridges may be loaded into an HPHT press.The substrates and volume of diamond particles are then processed underHPHT conditions in the presence of a catalyst that causes the diamondparticles to bond to one another to form a matrix of bonded diamondgrains defining a polycrystalline diamond (“PCD”) table. The catalyst isoften a metal-solvent catalyst, such as cobalt, nickel, iron, or alloysthereof that is used for promoting intergrowth of the diamond particles.

In one conventional approach for forming a PDC, a constituent of thecemented-carbide substrate, such as cobalt from a cobalt-cementedtungsten carbide substrate, liquefies and sweeps from a region adjacentto the volume of diamond particles into interstitial regions between thediamond particles during the HPHT process. The cobalt acts as a solventcatalyst to promote intergrowth between the diamond particles, whichresults in formation of bonded diamond grains. A solvent catalyst may bemixed with the diamond particles prior to subjecting the diamondparticles and substrate to the HPHT process.

In another conventional approach for forming a PDC, a sintered PCD tablemay be separately formed and then leached to remove solvent catalystfrom interstitial regions between bonded diamond grains. The leached PCDtable may be simultaneously HPHT bonded to a substrate and infiltratedwith a non-catalyst material, such as silicon, in a separate HPHTprocess. The silicon may infiltrate the interstitial regions of thesintered PCD table from which the solvent catalyst has been leached andreact with the diamond grains to form silicon carbide.

SUMMARY

Embodiments of the invention relate to methods of at least partiallyremoving a leaching agent and/or leaching by-products from a PCD body toclean the PCD body, and methods of fabricating leached PCD bodies andPDCs in which a removal agent is used to remove a leaching agent and/orleaching by-product from at least a portion of a leached PCD body.Pressurized fluid flow of the removal agent through the interstitialspaces in the leached PCD body may provide more rapid and effectiveremoval/cleaning of the leaching agent and/or leaching by-product from aPCD body than traditional soaking in a fluid.

In an embodiment, a method of cleaning an at least partially leached PCDbody is disclosed. A PCD body may be positioned in a pressure vesselsuch that at least one surface of the PCD body is exposed to anenvironment inside of the pressure vessel. The pressure vessel may be atleast partially filled with a removal agent. The pressure and/ortemperature in the pressure vessel may then be elevated above an ambientpressure and/or an ambient temperature in an environment outside thepressure vessel, at which point the removal agent may diffuse/flowthrough the PCD body, thereby dissolving, sweeping, combinationsthereof, or otherwise removing leaching agents and/or leachingby-products. In an embodiment, a fluid in a super critical state may beutilized as a removal agent component.

In an embodiment, a method of fabricating a PDC is disclosed. A PCD bodyis provided, which includes a plurality of bonded diamond grainsdefining a plurality of interstitial regions in which a catalyst isdisposed. The PCD body may then be leached with a leaching agent to atleast partially remove the catalyst from the PCD body. In an embodiment,the leaching agent may include a supercritical fluid component, anaqueous component, an organic component, or combinations of theforegoing. The at least partially leached PCD body may then be cleanedsubstantially as described above to at least partially remove theleaching agent and/or leaching by-products from the at least partiallyleached PCD body. After cleaning, the at least partially leached andcleaned polycrystalline diamond body may be bonded to a substrate toform a polycrystalline diamond compact

Features from any of the disclosed embodiments may be used incombination with one another, without limitation. In addition, otherfeatures and advantages of the present disclosure will become apparentto those of ordinary skill in the art through consideration of thefollowing detailed description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate several embodiments of the invention, whereinidentical reference numerals refer to identical or similar elements orfeatures in different views or embodiments shown in the drawings.

FIGS. 1A-1F are cross-sectional views illustrating different stages in amethod of fabricating a PDC in which a pressurized removal agent is usedfor cleaning a PCD body according to an embodiment.

FIG. 2A is a cross-sectional side view of a pressure vessel according toan embodiment.

FIG. 2B is a cross-sectional side view of a pressure vessel and removalagent supply according to an embodiment.

FIG. 2C is an isometric view of a pressure vessel according to anembodiment.

FIG. 3A is a flow diagram of a method of making a PDC according to anembodiment.

FIG. 3B is a flow diagram of a method of cleaning a PCD according to anembodiment.

FIG. 4 is an isometric view of a rotary drill bit according to anembodiment that may employ one or more of the PDCs fabricated accordingto any of the embodiments disclosed herein.

FIG. 5 is a top elevation view of the rotary drill bit shown in FIG. 4.

FIG. 6 is an isometric cut-away view of a thrust-bearing apparatusaccording to an embodiment, which may utilize any of the disclosed PDCfabricated according to any of the embodiments disclosed herein asbearing elements.

FIG. 7 is an isometric cut-away view of a radial bearing apparatusaccording to an embodiment, which may utilize any of the disclosed PDCfabricated according to any of the embodiments disclosed herein asbearing elements.

DETAILED DESCRIPTION

Embodiments of the invention relate to methods of at least partiallyremoving leaching agents and/or leaching by-products from a PCD body toclean the PCD body, and methods of fabricating leached PCD bodies andPDCs, resultant PCD bodies and PDCs, and applications for such PCDbodies and PDCs. Cleaning an at least partially leached PDC using aremoval agent under elevated pressure and/or elevated temperature,including pressure resulting in supercritical fluids, may provide rapidand efficient removal of leaching agents and/or leaching by-productsfrom the PCD body. The PDC embodiments disclosed herein may be used in avariety of applications, such as rotary drill bits, bearing apparatuses,wire-drawing dies, machining equipment, and other articles andapparatuses.

As used herein, “elevated pressure” or “elevated temperature” refers toa pressure or a temperature relative to ambient pressure or temperatureoutside of the leaching and/or pressure vessel. As used herein, “asupercritical fluid component” may refer to any substance at atemperature and pressure above its critical point, where a distinctliquid and gas phase boundary does not exist (i.e., fluid in asupercritical state) and/or any substance capable of being placed insuch a supercritical state. A supercritical fluid component can effusethrough solids like a gas, and may dissolve materials or have masstransport properties like a liquid.

FIGS. 1A-1F are cross-sectional views illustrating different stages in amethod of fabricating a PDC according to an embodiment that includesforming a PCD body from a plurality of diamond particles and a catalystin a first HPHT process and at least partially leaching the PCD bodyso-formed by exposing the PCD body to a leaching agent. The at leastpartially leached PCD body is exposed to a removal agent including, butnot limited to, an aqueous component, a supercritical fluid, an organiccomponent, an inorganic component, or combinations thereof underelevated pressure and/or temperature to remove leaching agent and/orleaching by-products from the PCD body, thereby cleaning the PCD body.Such a method may provide for more rapid and effective removal of theleaching agent and/or leaching by-products from the PCD body thanconventional diffusional cleaning processes. A PDC may be formed bybonding the at least partially leached and cleaned PCD body to asubstrate in a second HPHT process, which infiltrates the at leastpartially leached and cleaned PCD body with an infiltrant. The PDCso-formed may be subsequently shaped to provide a peripherally-extendingchamfer.

A PCD body may be formed by subjecting diamond particles in the presenceof a catalyst to HPHT sintering conditions. In embodiments, the catalystmay be in the form of a powder, a disc, a foil, or in a cemented carbidesubstrate. The PCD body may be formed independently from or integrallywith a substrate, both under HPHT conditions.

Referring to FIG. 1A, a cross-sectional view of an assembly 100 isillustrated in which a plurality of diamond particles 104 are placedadjacent to a substrate 108. A PCD body/table 124 as shown in FIG. 1Bmay be fabricated by subjecting the assembly 100 including the pluralityof diamond particles 104 (e.g., diamond particles having an averageparticle size between 0.5 μm to about 150 μm) and the substrate 108 toan HPHT sintering process in the presence of a catalyst. A suitablecatalyst may include a metal-solvent catalyst including but not limitedto, cobalt, nickel, iron; a carbonate catalyst; an alloy of any of thepreceding metals; or combinations of the preceding catalysts tofacilitate intergrowth between the diamond particles 104 and form thePCD body/table 124 (FIG. 1B) comprising directly bonded-together diamondgrains (e.g., exhibiting sp³ bonding) defining interstitial regions withthe catalyst disposed within at least a portion of the interstitialregions. In order to effectively sinter the plurality of diamondparticles 104 under HPHT conditions, the assembly 100, shown in FIG. 1A,may be placed in a pressure transmitting medium, such as a refractorymetal can, graphite structure, pyrophyllite or other pressuretransmitting structure, or another suitable container or supportingelement. The pressure transmitting medium, including the assembly 100,may be subjected to an HPHT process using an HPHT press at a temperatureof at least about 1000° C. (e.g., about 1300° C. to about 1600° C.) anda cell pressure of at least 4 GPa (e.g., about 5 GPa to about 10 GPa,about 7 GPa to about 9 GPa) for a time sufficient to sinter the diamondparticles 104 and form a PCD body/table 124 that bonds to the substrate108. In an embodiment, a PCD body 124 may be formed by sintering diamondparticles in an HPHT process without a substrate present. In anembodiment, a PCD body may be formed by sintering diamond particles 104in the presence of a catalyst not supplied from a substrate, by way ofnon-limiting example, a powder, a wafer/disc, or a foil.

In the illustrated embodiment FIG. 1B, the PCD body/table 124 is formedby sintering the diamond particles 104 in the presence of the substrate108 in a first HPHT process. The substrate 108 may include metal-solventcatalyst-cemented tungsten carbide from which metal-solvent catalyst(e.g., cobalt from a cobalt-cemented tungsten carbide substrate) ormetal-solvent catalyst alloy (e.g., cobalt alloy) infiltrates into thediamond particles 104 and catalyzes formation of PCD. For example, thesubstrate 108 may comprise a cemented carbide material, such as acobalt-cemented tungsten carbide material or another suitable material.For example, nickel, iron, and alloys thereof are other catalysts thatmay form part of the substrate 108. The substrate 108 may include,without limitation, cemented carbides including titanium carbide,niobium carbide, tantalum carbide, vanadium carbide, and combinations ofany of the preceding carbides cemented with iron, nickel, cobalt, oralloys thereof. However, in other embodiments, the substrate 108 may bereplaced with a catalyst material disc and/or catalyst particles may bemixed with the diamond particles 104. As discussed above, in otherembodiments, the catalyst may be a carbonate catalyst selected from oneor more alkali metal carbonates (e.g., one or more carbonates of Li, Na,and K), one or more alkaline earth metal carbonates (e.g., one or morecarbonates of Be, Mg, Ca, Sr, and Ba), or combinations of the foregoing.The carbonate catalyst may be partially or substantially completelyconverted to a corresponding oxide of Li, Na, K, Be, Mg, Ca, Sr, Ba, orcombinations after HPHT sintering of the plurality of diamond particles104.

The diamond particle size distribution of the plurality of diamondparticles 104 may exhibit a single mode, or may be a bimodal or greatergrain size distribution that may be substantially continuous ordiscontinuous. In an embodiment, the diamond particles 104 may comprisea relatively larger size and at least one relatively smaller size. Asused herein, the phrases “relatively larger” and “relatively smaller”refer to particle sizes (by any suitable method) that differ by at leasta factor of two (e.g., 30 μm and 15 μm). According to variousembodiments, the diamond particles 104 may include a portion exhibitinga relatively larger average particle size (e.g., 50 μm, 40 μm, 30 μm, 20μm, 15 μm, 12 μm, 10 μm, 8 μm) and another portion exhibiting at leastone relatively smaller average particle size (e.g., 6 μm, 5 μm, 4 μm, 3μm, 2 μm, 1 μm, 0.5 μm, less than 0.5 μm, 0.1 μm, less than 0.1 μm). Inan embodiment, the diamond particles 104 may include a portionexhibiting a relatively larger average particle size between about 10 μmand about 40 μm and another portion exhibiting a relatively smalleraverage particle size between about 1 μm and 4 μm. In some embodiments,the diamond particles 104 may comprise three or more different averageparticle sizes (e.g., one relatively larger average particle size andtwo or more relatively smaller average particle sizes), withoutlimitation.

FIG. 1B illustrates a cross-sectional view of a PDC 120 formed by HPHTprocessing of the assembly 100 shown in FIG. 1A. In such an embodiment,the PCD body/table 124 so-formed may include tungsten and/or tungstencarbide that is swept in with the catalyst from the substrate 108. Forexample, some tungsten and/or tungsten carbide from the substrate may bedissolved or otherwise transferred by the liquefied catalyst (e.g.,cobalt from a cobalt-cemented tungsten carbide substrate) of thesubstrate 108 that sweeps into the diamond particles 104. The PCDbody/table 124 includes a plurality of directly bonded-together diamondgrains exhibiting diamond-to-diamond bonding therebetween (e.g., sp³bonding) defining interstitial regions with the catalyst disposed withinat least a portion of the interstitial regions. The interstitial regionsmay be interconnected allowing material to sweep or diffuse through thePCD table through the interconnected interstitial regions. The PCDbody/table 124 also becomes metallurgically bonded to the substrate 108during HPHT processing of the assembly 100. In an embodiment, thesintered diamond grains of an at least partially leached PCD body 126(as shown in FIG. 1D) may exhibit an average grain size of about 20 μmor less.

More details about the manner in which the PDC 120 or the PCD body/table124 may be formed may be found in U.S. Pat. Nos. 7,866,418, 7,998,573,8,024,136, and 8,236,074 which are incorporated herein, in theirentirety, by this reference. U.S. Pat. No. 7,866,418 discloses variousembodiments for fabricating PCD and PDCs at ultra-high cell pressures.For example, PCD sintered at a cell pressure of at least about 7.5 GPamay exhibit a coercivity of 115 Oe or more, a high-degree ofdiamond-to-diamond bonding, a specific magnetic saturation of about 15G·cm³/g or less, and a metal-solvent catalyst content of about 7.5weight % (“wt. %”) or less, such as about 1 wt. % to about 6 wt. %,about 1 wt. % to about 3 wt. %, or about 3 wt. % to about 6 wt. %.Generally, as the sintering cell pressure that is used to form the PCDincreases, the coercivity may increase and the magnetic saturation maydecrease. The PCD defined collectively by the bonded diamond grains andthe catalyst may exhibit a coercivity of about 115 Oe or more and ametal-solvent catalyst content of less than about 7.5 wt. % (e.g., asmay be indicated by a specific magnetic saturation of about 15 G·cm³/gor less). In a more detailed embodiment, the coercivity of the PCD maybe about 115 Oe to about 250 Oe and the specific magnetic saturation ofthe PCD may be greater than 0 G·cm³/g to about 15 G·cm³/g. In an evenmore detailed embodiment, the coercivity of the PCD may be about 115 Oeto about 175 Oe and the specific magnetic saturation of the PCD may beabout 5 G·cm³/g to about 15 G·cm³/g. In yet an even more detailedembodiment, the coercivity of the PCD may be about 155 Oe to about 175Oe and the specific magnetic saturation of the PCD may be about 10G·cm³/g to about 15 G·cm³/g. The specific permeability (i.e., the ratioof specific magnetic saturation to coercivity) of the PCD may be about0.10 or less, such as about 0.060 to about 0.090. Despite the averagegrain size of the bonded diamond grains being less than about 30 μm insome embodiments, the catalyst content in the PCD may be less than about7.5 wt. % resulting in a desirable thermal stability.

The PCD body/table 124, shown in FIG. 1B, may be separated from thesubstrate 108 using a lapping process, a grinding process, wireelectrical discharge machining (“wire EDM”), combinations thereof, oranother suitable material-removal process. The separated PCD body/table124, as illustrated in FIG. 1C, may be enclosed in a suitable leachingvessel wherein a leaching agent may be provided that is selected toremove substantially all of the catalyst from the interstitial regionsof the separated PCD body/table 124 to form the at least partiallyleached PCD body 126 substantially as depicted in FIG. 1D. In anembodiment, the leaching vessel/process may be configured to flow oragitate the leaching agent around the PCD body/table 124 with, by way ofnon-limiting example a stir bar, fluid and/or gas flow inlets andoutlets, or an ultrasonic agitator, to form an at least partiallyleached PCD body 126.

In an embodiment, the PCD body/table 124 and the leaching agent may beplaced in the leaching vessel and allowed to soak until such time as thecatalyst is leached from the PCD body 124 to a satisfactory depth. In anembodiment, the PCD body/table 124 and the leaching agent may besubjected to elevated temperatures and pressures, thereby causing thecatalyst to be leached from the PCD body/table 124. As known in the art,by using elevated pressures and/or temperatures during the leachingprocess, the time necessary to satisfactorily leach a catalyst from aPCD body may be reduced.

Elevated pressure may be accomplished by utilizing a pressure vessel orany other type of vessel suitable to withstand pressures above ambientpressure. Pressurization may be accomplished by, for example, using apressure transmitting medium in combination with the pressure vessel,utilizing vapor pressure produced during heating of the leaching agentin a leaching vessel, a standard column of fluid, applying pressure viaa pump, or any other suitable method. Elevated pressure may be anypressure above ambient pressure of the environment outside of theleaching vessel.

Elevated temperatures in the leaching vessel may be accomplished in anynumber ways. For example, using a heating element in combination withthe leaching vessel, microwave transmission to the contents of theleaching vessel, induction heating, combinations or the foregoing, orany other suitable method may be used to heat the leaching agent and/orthe PCD body. Elevated temperature may be any temperature above ambienttemperature, but below the temperature of thermal degradation of thepolycrystalline diamond body (i.e., about 700° C. in non-diamond stableconditions). For example, the temperature of the leaching agent may beany temperature near the boiling point of the leaching agent (i.e., theboiling point at the pressure of the leaching agent), any temperatureabove the boiling point of the leaching agent, or any temperature below700° C. In an embodiment, both the pressure and the temperature may becontrolled in such a manner as to maintain the leaching agent or acomponent of the leaching agent in a supercritical state.

A leaching agent in a supercritical state may leach a PCD table fasterthan a conventional leaching agent bath. Leaching agents having asupercritical fluid component in the supercritical state and an aqueouscomponent have many advantages for the removal of metallic infiltrantand catalyst from PCD bodies over conventional leaching agents andprocesses including enhanced diffusivity, lower viscosity, chemicalstability, and/or pressure-dependent solvation properties that mayfacilitate removal of the catalyst. The supercritical fluid componentmay also exhibit substantially zero surface tension, which may bebeneficial for extraction of metallic infiltrant or catalyst from PCDbodies because the supercritical fluid component may more readilypenetrate into the interstitial regions between the bonded diamondgrains of the PCD body and facilitate increased mass transfer. Thesefeatures of supercritical fluid component may be exploited to leach thePCD bodies and PDCs to thereby remove metallic infiltrant or catalystfrom the interstitial regions, and to provide for shorter leachingcycles, and faster leaching rates compared to a conventional acidleaching process. Leaching using a supercritical fluid component may beparticularly effective for leaching PCD bodies fabricated at ultra-highcell pressures that exhibit a relatively high-degree ofdiamond-to-diamond bonding as described in U.S. Pat. No. 7,866,418. Forexample, it is currently believed that employing leaching agentsincluding a supercritical fluid component may improve leaching rates byas much as a factor of about 8 to about 10. Leaching with supercriticalagents or leaching agents comprising supercritical components may becarried out under the conditions described above or substantially as anyof the conditions described in U.S. Patent Application No. 61/897,764,the disclosure of which is incorporated herein, in its entirety, by thisreference.

After at least partially leaching the PCD body, the PCD body 126 may besubstantially free of catalyst material. However, not all of thecatalyst may be removed and as such the PCD body cannot be referred toas absolutely free of catalyst. For example, substantially free includessituations in which 85 wt. %, 90 wt. %, 95 wt. %, 97 wt. %, 99 wt. %,99.9 wt. %, or greater than 99 wt. % of the originally present catalystmaterial has been removed from the leached portion. The resulting atleast partially leached PCD body 126 includes a plurality ofinterstitial regions that were previously occupied by the catalyst andform a network of at least partially interconnected pores that extendbetween the surfaces of the at least partially leached PCD table 126.The at least partially interconnected pores may enable fluids and/orgases to diffuse into the PCD body 126, and/or from one surface of thePCD body through to another surface of the PCD body.

It is believed that after leaching, leaching agents (e.g., aqua regia)and/or leaching by-products (e.g., cobalt ions, or cobalt salts) maydiffuse toward the surface of a PCD body. For example, the leachingagent used to remove cobalt from the interstitial regions may leave oneor more residual salts, one or more oxides, complexes, combinations ofthe foregoing, or another leaching by-product within at least a portionof the interstitial regions of the at least partially leached PCDbody/table 126. Depending upon the chemistry of the leaching solution,the leaching by-products may comprise a salt of nitric acid,hydrofluoric acid, hydrochloric acid, phosphoric acid, acetic acid, ormixtures of the foregoing. For example, the salt may be cobalt nitrateor cobalt chloride. The leaching by-products may alternatively or incombination include a metal oxide, such as an oxide of tungsten, cobaltor other metal-solvent catalyst, and/or a hydrated ion or another typeof metal present in the catalyst of the at least partially leached PCDbody/table prior to leaching. It has been observed that PCD bodiescontaining leaching by-products exhibit increased difficulty in beingbonded to a substrate. For example, leaching by-products may block,obstruct, or otherwise inhibit infiltration of the at least partiallyleached PCD body/table 126 with a Group VIII infiltrant material (e.g.,cobalt). Such leaching by-products may also inhibit back filling withother materials such as silicon or copper. Removing leaching by-productsprior to infiltration may provide greater thermal stability by allowingmore infiltrant to infiltrate the PCD body.

Conventional PCD table cleaning processes include soaking the at leastpartially leached PCD body/table 126 in a solution. Conventional removalsolutions or agents include de-ionized water. Conventional soaking timesfor cleaning leaching agents and/or leaching by-products out of a PCDbody may be relatively long, ranging from days to weeks. U.S. Pat. No.7,845,438, which is incorporated herein in its entirety by thisreference, discloses various techniques for cleaning leachingby-products from a PCD body.

Referring to FIG. 2A leaching agents and/or leaching agent by-productsmay be removed/cleaned from the at least partially leached PCD table 126by subjecting the at least partially leached PCD table 126 to apressurized removal process described in greater detail below, therebyproducing the at least partially leached and cleaned PCD table 128depicted in FIG. 1E. In an embodiment, the at least partially leachedPCD table 126 may be exposed to removal agents 152 at elevated pressureson at least one surface of the at least partially leached PCD table 126.Portions of the at least partially leached PCD table 126 subjected tothe elevated pressures may be referred to as the high pressure surfaces162. In an embodiment, the removal agents 152 may pass through the atleast partially leached PCD table 126 from the high pressure surface 162to a low pressure surface 164 exposed to an ambient or lower outsideenvironment pressure, thereby removing/cleaning the leaching agentsand/or leaching by-products from the at least partially leached PCDtable 126.

In an embodiment depicted in FIG. 1F, an at least partially leached,cleaned, and infiltrated PCD table 130 may be infiltrated to include atleast one region 131 and/or 132, wherein the regions may include ametallic infiltrant such as cobalt, silicon, copper, tin, aluminum,boron, combinations thereof, or any of the other infiltrant materialsdiscussed herein. In an embodiment, the first region 131 may besubstantially free of cobalt infiltrant but include another infiltrant(e.g., copper) within the interstitial regions. In an embodiment, thesecond infiltrated region 132 may be disposed nearest the substrate andinclude a metallic infiltrant (e.g., cobalt from a cobalt-cementedtungsten carbide substrate such as the substrate 108) in theinterstitial regions therein. In other embodiments, the infiltrated PCDtable 130 may be fully infiltrated such that the first region 131 alsoincludes the metallic infiltrant therein. When the infiltrated PCD table130 is partially or fully infiltrated with the metallic infiltrant, theinfiltrated PCD table 130 may be at least partially leached to aselected depth from an upper surface to at least partially remove themetallic infiltrant. For example, the selected depth may be greater thanabout 50 μm, such as about 50 μm to about 800 μm, about 200 μm to about800 μm, about 400 μm to about 800 μm, or about 250 μm to about 500 μm.In some embodiments, the at least partially leached PCD table 126 may bechamfered so that a chamfer is formed between the upper surface and sidesurface, or the chamfer may be formed after infiltration of the at leastpartially leached PCD table 126.

Referring still to FIG. 2A, in an embodiment, the at least partiallyleached PCD table 126 is cleaned in a pressure vessel 150. The pressurevessel 150 may include a vessel configured hold a pressure above that ofan ambient atmospheric pressure, such as being configured to holdpressures in excess of 50 MPa; to contain chemicals including strongacids, strong bases, organic solvents, or combinations thereof; tomaintain integrity at elevated temperatures, such as under 700° C.; andcombinations of the foregoing. Put another way, the pressure vessel 150may include a vessel configured to be capable of withstanding conditionsnecessary to create and/or maintain supercritical fluid states. In anembodiment, the pressure vessel 150 may comprise a stainless steelvessel, or a stainless steel vessel lined with polytetrafluoroethylene(“PTFE”). In an embodiment, the pressure vessel 150 may comprise atleast one side wall 153, a back wall 154, and a pressure cap 170, all ofwhich are configured to hold the removal agent 152, maintain structuralintegrity and/or pressure and heat maintaining capabilities underelevated pressure and/or temperature.

In an embodiment of the pressure vessel 150 shown in FIG. 2A, the atleast one side wall 153 is joined to the back wall 154. The pressure cap170 may optionally include a pressure valve 172. In an embodiment, theleast partially leached PCD table 126 may be cleaned by placing theleast partially leached PCD table 126 into the pressure vessel 150 withthe removal agent 152. The pressure is elevated inside of the pressurevessel 150. In an embodiment, the pressure vessel 150 may include anengaging end 155 defined at least partially by the side wall 153, withthe engaging end 155 being disposed generally opposite the back wall154. The engaging end 155 may be configured to engage and hold the atleast partially leached PCD table 126 in place such that it is retainedinside of the pressure vessel 150 during the pressurizedremoval/cleaning methods described herein. The engaging end 155 may beconfigured to retain the at least partially leached PCD table 126, forexample by an interference or compression fit. In an embodiment, theinterference fit may be accomplished using at least a single sealingelement 158. The sealing element 158 may comprise a gasket, an O-ring,compression seal (ferrule), sleeve, or any other suitable device forproviding a seal between two surfaces.

In another embodiment depicted in FIG. 2B, the at least partiallyleached PCD table 126 may be positioned on the engaging end 155 byinsertion into a retaining ring 159. The retaining ring 159 may beconfigured to include at least a single lip 160 in which movement of theat least partially leached PCD table 126 is constrained by at least theat least a single lip 160. The retaining ring 159 may be threaded toattach to a complimentary thread on the at least one single side wall153. The at least partially leached PCD table 126 may abut a landing 161inside of the at least one side wall 153. The retaining ring 159includes threads therein may then be threadedly attached to the at leastone side wall 153 having complementary threads to thereby secure the atleast partially leached PCD table 126 in place in the pressure vessel150. In an embodiment, the pressure vessel 150 may be secured to theretaining ring 159 by another mechanical means such as screws, bolts,lock studs, clamps, combinations thereof, or any other means configuredto hold two components together.

Referring again to FIG. 2A, in an embodiment, the pressure cap 170 isconfigured to contain elevated pressures inside of the pressure vessel150 and release the elevated pressure upon opening the pressure valve172. It will be understood that in certain embodiments, the pressure cap170 is not necessary to build the pressures disclosed herein. Forexample, in an embodiment, elevated pressure may be supplied from aninlet 156, or may be supplied from the interior volume 151 wherein theat least partially leached PCD table 126 holds some of the elevatedpressure behind the high pressure surface 162 in the interior volume151. In an embodiment substantially as depicted in FIG. 2B, elevatedpressure may be achieved by sealing (i.e., positioning) at leastpartially leached PCD table 126 at the engaging end 155 wherein the atleast partially leached PCD table 126 seals the pressure vessel 150 atthe engaging end 155 by having the same or substantially the samegeometry as the engaging end 155 and fitting closely therein such thatgases or fluids are not readily lost where the at least partiallyleached PCD table 126 and engaging end 155 meet. It will be readilyunderstood that the at least partially leached PCD table 126, being atleast partially porous through interconnected interstitial spaces, maynot hold the pressure inside of the interior volume 151 indefinitely,however, the PCD table will be able to hold the pressure before slowlylosing such pressure through migration, flow, or diffusion of gasesand/or fluids from the high pressure surface 162 through theinterconnected interstitial spaces of the bonded polycrystalline diamondgrains to the lower pressure environment outside of the interior volume151.

The interior volume 151 is defined partially by the at least one sidewall 153 joined to the back wall 154. The interior volume 151 may befurther defined by the pressure cap 170. In such an embodiment,substantially all of the inside of the pressure vessel 150 may comprisethe interior volume 151. In an embodiment, the interior volume 151 maybe further defined by at least one surface of the PCD table 126. In suchan embodiment, the interior volume 151 may comprise only a portion ofthe inside of the pressure vessel 150, such as the embodiment depictedin FIG. 2A. The interior volume 151 may include a removal agent 152,elevated pressure, elevated temperature, or combinations thereof. Asdescribed in more detail below, the removal agent 152 may comprise, forexample, a liquid, a gas, or combinations thereof. The removal agent 152may be supplied to the interior volume 151 before, substantiallycontemporaneously with, and/or after the at least partially leached PCDtable 126 is positioned on the pressure vessel 150.

In an embodiment, the removal agent 152 may be supplied to the inside ofthe pressure vessel 150 as an aliquot by a syringe, pipette, flask,beaker, or other chemical dispensing means. In an embodiment depicted inFIG. 2B, the removal agent 152 may be supplied to the inside of thepressure vessel 150′, specifically to the interior volume 151, via aninlet 156. The inlet 156 may be configured to deliver at least a singlecomponent of the removal agent 152. In an embodiment depicted in FIG.2A, the pressure vessel 150 may optionally include one or more inlets156, with the individual inlets configured to deliver individualcomponents of the removal agent 152, pressurization from a pressuresource (i.e., a pressure pump (not shown)), a heating system, orcombinations thereof. In an embodiment, the pressure vessel 150 mayinclude a heating system 169. The heating system 169 may be positionedinternal (as depicted in FIG. 2B) and/or external to the pressure vessel150.

In an embodiment depicted in FIG. 2B, the pressure vessel 150′ may beconnected to the inlet 156 and further connected to a removal agentsupply 165 configured to supply removal agent 152 into the pressurevessel 150′ under the desired conditions, including, but not limited to,removal agent composition, temperature, pressure, and combinationsthereof. For example, the removal agent supply 165 may comprise one ormore of a supercritical component source 166, a removal agent componentsource 167, a pressure source 168, the heating system 169, and a stirrer157. The removal agent component source 167 may be configured to supplyone or more of an aqueous component including an acidic component and/ora basic component; an organic solvent component; an inorganic component;and a chelating agent component. The supercritical component source 166may be configured to deliver a fluid or gas capable of being manipulatedinto the supercritical fluid state by control of pressure andtemperature conditions. By way of non-limiting example, de-ionized waterand carbon dioxide are suitable supercritical components for the removalagent 152. As depicted in FIG. 2A, the pressure vessel 150 may havemultiple inlets 156, the multiple inlets 156 configured to individuallydeliver substantially the same components described above regarding theremoval agent supply 165.

The heating system 169 may include one or more heating elements, adielectric heat source such as a microwave or radio wave emitter, or oneor more induction heating elements. The pressure source 168 may providepressure to the removal agent supply 165 and/or the pressure vessel 150by via a pressure pump, or a pressure transmitting medium in thepressure vessel 150.

In an embodiment, the pressure vessel 150″ may comprise a retainingfeature 163 as shown in FIG. 2C which attaches to the pressure vessel150″ near the engaging end 155 and holds the PCD body 124 in place. Theretaining feature 163 may be configured to prevent the PCD table fromlosing its position during pressurized cleaning and/or to providesupport to the PCD table 124 during pressurized cleaning. In anembodiment, the retaining feature may resemble a wire cage over the lowpressure surface 164 attached to the pressure vessel 150″.

In an embodiment, a suitable vessel for cleaning may comprise a trayhaving multiple pressure vessels, substantially similar to any describedabove, formed or disposed therein, wherein cleaning PCD bodies underpressurized conditions may be performed in batches.

FIG. 3A is a flow diagram of a method 300 of making a PDC according toan embodiment, the method 300 includes an act 310 of forming a PCD table124 in substantially any manner described above. Following the act 310of forming a PCD table, an act 320 of at least partially leaching thePCD table is carried out in substantially the same manner as any of theleaching methods describe above. Next, an act 330 of at least partiallyremoving at least one leaching by-product and/or at least one leachingagent from the at least partially leached PCD table to clean the atleast partially leached PCD table is performed in a pressure vessel atan elevated pressure and/or temperature. Optionally, and as detailedmore below, an act 335 of infiltrating the at least partially leachedand cleaned PCD table may be carried out after the act 330 of at leastpartially removing at least one leaching by-product and/or at least oneleaching agent from the at least partially leached PCD table. Forexample, the PCD table 124 may be infiltrated with an infiltrant duringHPHT bonding of the PCD table 128 to the substrate 108, or in a separateHPHT or non-HPHT process. Following the act 330 of at least partiallyremoving at least one leaching by-product and/or at least one leachingagent from the at least partially leached PCD table, a PDC may be formedvia the act 340 of bonding the at least partially leached and cleanedPCD table to a substrate.

FIG. 3B is a flow diagram of an embodiment of a method 330 of at leastpartially removing at least one leaching by-product and/or at least oneleaching agent from the at least partially leached PCD table to cleanthe at least partially leached PCD table including an act 332 ofpositioning a PCD body in a pressure vessel, wherein an act 334 of atleast partially filling the pressure vessel with a removal agent iscarried out. Referring to FIGS. 2A-2C as it relates to FIG. 3B, an act336 of elevating at least the pressure of the removal agent includeselevating the pressure of the removal agent either in the pressurevessel 150 or in a removal agent supply 165. An act 338 of exposing theat least partially leached PCD table to the removal agent may includediffusing the removal agent through the PCD body which further includesflowing the removal agent 152 into the PCD table and/or through the PCDtable from the high pressure surface 162 (FIG. 2A) to the low pressuresurface 164 (FIG. 2A), thereby sweeping or cleaning out any leachingagents or leaching agent by-products in the at least partially leachedPCD table 126.

In an embodiment, the act 332 of positioning a PCD table in a pressurevessel includes, placing the PCD body 126 into the pressure vessel. Inan embodiment, the act 332 of positioning a PCD table in a pressurevessel includes, placing the PCD table 126 in the pressure vessel andsealing the interior volume of the pressure vessel from the environmentoutside of the pressure vessel. Also with reference to FIG. 2A, in anembodiment, the act 332 of positioning a PCD table in a pressure vesselincludes placing the at least partially leached PCD table 126 in thepressure vessel 150 such that at least one surface of the at leastpartially leached PCD table 126 is exposed to the removal agent withinthe pressure vessel 150. In an embodiment, the act 332 of positioning aPCD table in a pressure vessel includes, placing the at least partiallyleached PCD body 126 into the pressure vessel 150 such that all of thesurfaces of the at least partially leached PCD table 126 are exposed tothe removal agent within the pressure vessel 150.

In an embodiment, the act 332 of positioning a PCD table in a pressurevessel includes, placing the at least partially leached PCD table 126into the pressure vessel such that the at least partially leached PCDtable 126 encloses or otherwise seals a portion of the pressure vessel150, thereby creating an interior volume 151. In embodiments, the act332 of positioning a PCD table in a pressure vessel 150 includes,positioning the at least partially leached PCD table 126 inside of thepressure vessel 150 such that the PCD table includes one or more highpressure surfaces 162 exposed to the environment inside of the pressurevessel 150 (e.g., a removal agent therein). The act 332 of positioning aPCD table in a pressure vessel 150 may include, positioning the at leastpartially leached PCD table 126 in the pressure vessel 150 such that thePCD table includes one or more low pressure surfaces 164 (FIG. 2A)exposed to an environment outside of the pressure vessel 150. In anembodiment, the act 332 of positioning a PCD table in a pressure vessel150 includes, positioning the at least partially leached PCD table 126in a pressure vessel 150 such that the PCD table comprises both of oneor more high pressure surfaces 162 (FIG. 2A) exposed to the environmentinside of the pressure vessel 150 (including removal agent(s) therein)and one or more low pressure surfaces 164 (FIG. 2A) exposed to theenvironment outside of the pressure vessel 150. The at least partiallyleached PCD table 126 may be positioned in the pressure vessel 150 suchthat pressure exerted from the interior volume 151 on the high pressuresurface 162 (FIG. 2A) of at least partially leached PCD table 126 willnot dislodge the at least partially leached PCD table 126 from thepressure vessel 150. In an embodiment, the act 332 of positioning thePCD body in the pressure vessel includes, fitting the at least partiallyleached PCD table 126 into the engaging end 155 by tension fit, therebysecuring the PCD table in place. In an embodiment, at least a singlesealing element 158 may be used to create tension to hold the PCD bodyin place during the pressurized cleaning methods disclosed herein. In anembodiment, press fitting includes pressing the PCD body into thepressure vessel 150 by hand, by using a mallet or hammer, by othermechanical means, or combinations of the foregoing. Press fitting may beaccomplished using any pressing technique, by way of non-limitingexample, an arbor press, a pneumatic press, a hydraulic press, orcombinations thereof.

The act 332 of positioning a PCD body in a pressure vessel may includeattaching a retaining feature 163 to the pressure vessel 150, whereinthe retaining feature 163 is positioned adjacent to and contacts the atleast partially leached PCD table 126 on at least a single point to holdthe PCD table 124 in place from the outside or low pressure surface 164.

In an embodiment, the act 332 of positioning a PCD table includesplacing the PCD body 126 on the landing 161 of the at least one sidewall 153 (as shown in FIG. 2B), and connecting a retaining ring 159including the lip 160 and threading or attachment means complementary tothat of the side walls 153 to the at last one side wall 153.Accordingly, the at least partially leached PCD table 126 may be held inplace during cleaning by at least the forces applied to the PCD body bythe lip 160 and the landing 161. The retaining ring 159 may be held inplace on the pressure vessel 150 by fasteners, including but not limitedto bolts, screws, lock studs, or clamps. In an embodiment, the at leastpartially leached PCD table 126 is placed on the lip 160 of theretaining ring 159 which may then be attached to the pressure vessel 150as described above, such that the PCD table engages the landing 161 onthe side wall 153, thereby fixing the position of the at least partiallyleached PCD table 126 in place. Optionally, the sealing element 158(e.g., O-ring, gasket, compression seal, other seal element, orcombinations thereof) may be used between the PCD table 126 and thelanding 161. In an embodiment, the retaining ring 159 and/or features ofthe retaining ring 159 may be integrally formed or otherwise disposed onthe pressure cap 170 shown in FIG. 2A.

In an embodiment, the act 334 of at least partially filling the pressurevessel with a removal agent includes, placing or otherwise supplying atleast a single component of a removal agent 152 into the inside of thepressure vessel 150. In an embodiment, the act 334 of at least partiallyfilling the pressure vessel with a removal agent includes, supplying aremoval agent 152 in interior volume 151 of the pressure vessel 150. Inembodiments, suitable removal agents 152 may comprise one or morecomponents and/or one or more concentrations of components. Suitableremoval agent components may include those configured to dissolve orotherwise remove the leaching agents and/or leaching by-productsremaining in an at least partially leached PCD table 126 after leaching.Suitable removal agent components may include aqueous components, forexample, acidic or basic solutions; organic solvents; chelating agents;a supercritical component including at least one of water or carbondioxide; or combinations thereof. Removal agents may include any of theleaching agents and/or components of leaching agents described herein.Similar to those described above for leaching agents, components ofremoval agents 152 may be configured to react with, dissolve, orotherwise dispose of the leaching agents and/or leaching agentby-products left in the at least partially leached PCD table 126. Forexample, if it is desired that the removal agent 152 dissolve and/orsweep out residual leaching by-products in an at least partially leachedPCD table, an aqueous component and/or supercritical water or carbondioxide may be used. The aqueous component functions to dissolve and/orsweep out the leaching agents and/or by-products of leaching agentsincluding salts of leaching agents and metallic infiltrants or catalystsin solution as metal ions (e.g., cobalt ions). The aqueous component mayinclude, by way of non-limiting example, water (e.g., de-ionized water),hydrofluoric acid, nitric acid, hydrochloric acid, aqua regia,phosphoric acid, potassium permanganate, a sodium hydroxide solution, apotassium hydroxide solution, a lithium hydroxide solution, orcombinations thereof. When present, the chelating component, mayfunction to encapsulate the metal ions, which ordinarily are not verysoluble in the supercritical fluid component, into the supercriticalfluid component. In an embodiment, the supercritical fluid componentfunctions to dissolve; carry aqueous, organic, or chelating componentsto; and/or sweep out any leaching agents and/or leaching agentby-products remaining in the at least partially leached PCD table 126after leaching. The supercritical fluid component may include carbondioxide, water, organic fluids, or combinations thereof. In anembodiment, the supercritical fluid component may be combined with anorganic solvent, such as, by way of non-limiting example, methane,ethane, propane, ethylene, propylene, methanol, ethanol, acetone,pentane, butane, sulfur hexafluoride, xenon dichlorodifluoromethane,trifluoromethane, isopropanol, nitrous oxide, ammonia, methylamine,diethyl ether, or combinations thereof.

According to various embodiments, the aqueous component may compriseabout 5 wt. % to about 100 wt. % (e.g., about 10 wt. % to about 30 wt.%, about 15 wt. % to about 20 wt. %, about 30 wt. % to about 95 wt. %),the supercritical component may comprise about 5 wt. % to about 100 wt.% (e.g., about 10 wt. % to about 30 wt. %, about 15 wt. % to about 20wt. %, about 30 wt. % to about 100 wt. %), and the optional chelatingagent may comprise about 5 wt. % to about 60 wt. % (e.g., about 10 wt. %to about 30 wt. %, about 15 wt. % to about 20 wt. %, about 30 wt. % toabout 60 wt. %) of the removal agent 152. The removal agent 152 maycomprise any combination of any of the aqueous components, supercriticalcomponents, and chelating agents disclosed herein along with anycombination of the weight percent ranges disclosed above. While removalagents may comprise components capable of being placed in asupercritical state (i.e., supercritical components) during theprocesses described herein, it is understood that in embodiments, thesupercritical component does not have to be placed in a supercriticalstate for the cleaning/removal processes describe herein to effectivelyremove leaching by-products from a PCD table. For example, a removalagent comprising a component capable of being placed in a supercriticalstate may effectively clean the leaching by-products from a PCD bodyunder elevated pressure and optionally elevated temperature short of thesupercritical pressure and temperature of that component.

As discussed above regarding leaching agents, in order to facilitate thesolubility of the metal ions from the metallic infiltrant or catalyst inthe leaching agent by-product, a surfactant may be added to the removalagent to form an emulsion or microemulsion supercritical fluid. Theresulting microemulsion exhibiting polar metal or catalyst ions in watercores substantially disperses in the supercritical fluid componentmaking the emulsion supercritical fluid an effective medium for theremoval of metallic infiltrant or catalyst bound in leaching agentby-product from PCD bodies. For example, in some embodiments, theremoval agent 152 may include a chelating component (e.g., anamphiphilic surfactant) in addition to the supercritical fluid componentand the aqueous component. For example, the chelating component mayinclude at least one of an organic solvent, sodiumbis-(2-ethylhexyl)sulfosuccinate, a fluorinated sodiumbis-(2-ethylhexyl)sulfosuccinate, a perfluoropolyether phosphate, asurfactant including a fluorocarbon tail, or a surfactant including alow density of polarizability. In a more specific embodiment, theremoval agent 152 includes a microemulsion of supercritical carbondioxide, water, sodium bis-(2-ethylhexyl)sulfosuccinate, andperfluoropolyether phosphate. In an embodiment, when the supercriticalfluid component is supercritical water, the removal agent 152 may besubstantially free of the chelating agent as the leaching agentby-products may be soluble in water and metal ions are soluble in thesupercritical water.

In an embodiment, the removal agent 152 may be prepared by stirring ormixing the components, before, during, and/or after the act 334 of atleast partially filling the pressure vessel. For example, in anembodiment, a supercritical fluid component and the chelating componentmay be stirred or mixed sufficiently to form an emulsion, for example bya stirrer 157 disposed in the pressure vessel 150 or removal agentsupply 165 substantially as depicted in FIGS. 2A and 2B. Emulsificationmay occur following a period of stirring. For example, emulsificationmay occur following stirring for a time of less than about 2 hours, lessthan about 1.5 hours, from about 15 minutes to about 1 hour, from about20 minutes to about 40 minutes, from about 25 to about 35 minutes, orfor greater than 20 minutes. The stirring of the supercritical fluidcomponent and the chelating component may provide for a substantiallyhomogeneously dispersed emulsion.

In an embodiment, the act 334 of at least partially filling the pressurevessel with a removal agent includes placing at least one component ofthe removal agent 152 into the pressure vessel 150 before the act 332 ofpositioning the PCD table in the pressure vessel. In an embodiment,placing at least one component of a removal agent 152 into the pressurevessel 150 may comprise one or more of placing the at least one removalagent component into the vessel via a dispensing means including but notlimited to pipetting, pouring, pumping, opening a valve, and inputtingcommands into a computer controlled dispensing apparatus. In anembodiment, the act 334 of at least partially filling the pressurevessel with a removal agent includes placing at least one component of aremoval agent 152 into the pressure vessel 150 substantiallycontemporaneous with the act 332 of positioning the PCD table in thepressure vessel 150. In an embodiment, at least one component of aremoval agent 152 may be placed into the pressure vessel substantiallycontemporaneous with the act of positioning 332, by at least partiallyfilling the pressure vessel 150 with at least one component of a removalagent 152 from at least a single inlet 156, during or very near in timeto the act of positioning 332 as described above. In an embodiment, theact 334 of at least partially filling the pressure vessel with theremoval agent includes placing at least one component of the removalagent 152 into the pressure vessel 150 after the act 332 of positioningthe PCD table in the pressure vessel. This may be accomplished using theinlet 156 depicted in FIGS. 2A and 2B.

In an embodiment, the act 334 of at least partially filling the pressurevessel with a removal agent includes, at least partially filling thepressure vessel using at least one inlet 156. In an embodimentsubstantially as depicted in FIG. 2B, the inlet 156 may supply theremoval agent 152 including all of the removal agent components to thepressure vessel 150. In an embodiment substantially as depicted in FIG.2A, more than one inlet 156 may supply individual components of theremoval agent 152. For example, in an embodiment, the act 334 of atleast partially filling the pressure vessel with a removal agentincludes filling the pressure vessel 150 with a removal agent 152 byadding individual removal components into the pressure vessel throughseparate inlets 156. In an embodiment, more removal agent may be addedduring cleaning via at least a single inlet 156. In an embodiment, theact 334 includes adding and/or adjusting the component mixture of aremoval agent in-situ by adding at least a single removal agentcomponent while the at least partially leached PCD table 126 is beingplaced in the pressure vessel 150 and/or diffused through the at leastpartially leached PCD table 126 in act 338 described below. Adding oradjusting the component mixture of the removal agent in-situ may includeadding at least a single component of the removal agent 152 after thepressure vessel 150 has been substantially sealed. By way ofnon-limiting example, the removal agent 152 may be adjusted in-situbased on criteria including but not limited to removal agentcomposition, time, pressure, and temperature. In an embodiment, theremoval agent 152 may be adjusted from acidic or basic to neutral basedelapsed cleaning time; from neutral to acidic or basic over a periodbased on elapsed cleaning time, temperature, pressure or combinationsthereof; adjusted to contain a chelating agent or organic solvent onlyafter certain conditions are met; or combinations of the foregoing.Combinations of and criteria for adjusting any of the removal agentcomponents described herein are contemplated and may be used in addingto or adjusting the removal agent according to the methods describedherein.

The act 330 of removing at least one leaching by-product or at least oneleaching agent from the at least partially leached PCD table furtherincludes an act 336 of elevating at least a pressure of the removalagent. In an embodiment, the pressure of the removal agent may beelevated inside of the pressure vessel 150 to facilitate diffusion ofthe removal agent 152 into the at least partially leached PCD table 126.In an embodiment, the pressure on a removal agent may be elevated in theinterior volume 151 of the pressure vessel 150 to facilitate diffusingthe removal agent 152 from the high pressure surface 162 to the lowpressure surface 164 of the at least partially leached PCD table 126,substantially as depicted in FIGS. 2A-2C. In an embodiment, the act 336of elevating at least a pressure of the removal agent comprises using apressure pump to elevate the pressure inside of the pressure vessel 152.Using a pressure pump may include pumping at least one removal agentcomponent into the sealed pressure vessel 150 above the ambient pressureof the environment outside of the pressure vessel, thereby raising thepressure inside of the pressure vessel. In an embodiment, removing aleaching agent from a PCD body may include, elevating the pressureinside of a pressure vessel having acid and an at least partiallyleached PCD table disposed therein. In an embodiment, removing aleaching agent from a PCD body may include, elevating the pressureinside of a pressure vessel 150 having caustic soda and an at leastpartially leached PCD table disposed therein.

In an embodiment, suitable pressures of the removal agent 152 generatedby the pressure vessel 150 may include pressures of less than about 50MPa, about 45 MPa, about 25 MPa, about 22.5 MPa, about 20 MPa, about 15MPa, about 10 MPa, about 7.5 MPa, about 5 MPa, about 1 MPa, or aboveabout 0.105 MPa. In an embodiment, suitable ranges of pressures mayinclude pressures of less than about 50 MPa to pressures slightly aboveambient pressure (i.e., about 0.105 MPA), about 35 MPa to about 7.5 MPa,about 25 MPa to about 15 MPa, or about 20 MPa to about 22.5 MPa.

In an embodiment, the act 336 of elevating at least a pressure of theremoval agent includes elevating the temperature of at least a singlecomponent of the removal agent 152 inside of a substantially sealedpressure vessel, thereby inducing heightened vapor pressure. In anembodiment, elevating the pressure of the removal agent inside of thepressure vessel may be accomplished by heating the contents of thepressure vessel 150, including a removal agent 152, with a heatingelement 169 disposed inside and/or outside of the pressure vessel 150.In an embodiment, the act 336 may include placing the pressure vessel ina kiln, oven, or a heated bath, such as a salt bath. In an embodiment,the act 336 of elevating at least a pressure of the removal agentincludes heating the pressure vessel and/or the contents of the pressurevessel with a dielectric heat source such as a microwave or radio waveemitter to induce heightened vapor pressure therein. In an embodiment,the act 336 of elevating the pressure of the removal agent includesheating an acid or a base disposed in a pressure vessel to inducedelevated vapor pressure in the pressure vessel to diffuse the acid orbase into a PCD table.

Suitable cleaning temperatures may include temperatures above ambienttemperature and below about 700° C. Suitable temperatures may includeabout 650° C., about 500° C., about 400° C., about 300° C., about 200°C., about 100° C., and about 40° C. Suitable ranges may include about350° C. to about 400° C., about 250° C. to about 500° C., about 150° C.to about 600° C., and about 30° C. to about 700° C.

In an embodiment, the act 336 of elevating at least the pressure of theremoval agent includes, elevating both of the pressure and temperatureof the removal agent 152 such that the supercritical component in theremoval agent 152 enters a supercritical state. In an embodiment, carbondioxide may be a removal agent component, wherein the carbon dioxide maybe subjected to pressure above about 7.3 MPa and temperature above about31° C. thereby bringing the carbon dioxide to a supercritical state. Inan embodiment, de-ionized water may be a removal agent component,wherein the de-ionized water may be subjected to pressure above about22.1 MPa and temperature above about 374° C. to bring the water to asupercritical state. Any of the techniques suitable for elevating thetemperature and/or pressure of the contents of the pressure vessel,including but not limited to those described above, may be used to bringa removal agent component to its supercritical fluid state. Cleaning theat least partially leached PCD table 126 with supercritical fluid hasmany advantages for the at least partial removal of leaching agents andleaching by-products including the catalyst from PCD bodies over soakingin a solution including enhanced diffusivity, lower viscosity, chemicalstability, and pressure-dependent solvation properties that facilitateremoval of the leaching agents and leaching by-products including anycatalyst material present. The supercritical fluid component may alsoexhibit substantially zero surface tension, which is beneficial forcleaning PCD bodies because the supercritical fluid component may morereadily penetrate into the interstitial regions between the bondeddiamond grains of the PCD body. Accordingly, the removal agent havingthe supercritical component in the supercritical state may more quicklyand effectively diffuse through the PCD body, or from high pressure tolow pressure through a PCD body, thereby cleaning, dissolving, and/orsweeping leaching agents and leaching by-products from the PCD body.Further, as noted above regarding leaching agents, an emulsified removalagent having a component in a supercritical fluid state may moreeffectively carry removal agent components capable of dissolvingleaching agents and or leaching by-products into the interstitialregions between the bonded diamonds.

It will be readily understood that depending on the pressure vesselused, the pressure of the removal agent may be elevated before theremoval agent is introduced into the pressure vessel 150. Therefore,acts 332, 334, and 336 may be carried out in a different order thandepicted in FIG. 3B, depending on the desired effects and the type ofpressure vessel used. In an embodiment the act 336 of elevating at leastthe pressure of the removal agent may be carried out before positioningthe PCD table in the pressure vessel and/or before the act 334 of atleast partially filling the pressure vessel with the removal agent.

In an embodiment, the act 330 of removing at least one leachingby-product or at least one leaching agent from the at least partiallyleached PCD table may further include the act 338 of exposing thepolycrystalline diamond table to the removal agent (e.g., diffusing theremoval agent through the PCD body). In an embodiment, the removal agent152 disposed in the sealed pressure vessel 150 under pressurizedconditions, diffuses into the interstitial regions between bondeddiamond grains of the at least partially leached PCD table 126. In anembodiment, the removal agent 152 is allowed to diffuse, flow, orotherwise migrate from high pressure in the interior volume 151 to lowerpressure outside of the interior volume. The removal agent 152 maydiffuse from the high pressure surface 162 to the low pressure surface164 dissolving, sweeping or otherwise disposing of the leaching agentsand/or leaching by-products remaining in the partially leached PCD body126. In an embodiment, the leaching agent 150 may diffuse through thePCD table 124 in one or more of a gas phase, a liquid phase, and asupercritical phase.

In an embodiment, the pressure cap 170, as shown in FIG. 2A, may be usedin part to create elevated pressure in the pressure vessel 150 or morespecifically in the interior volume 151. In an embodiment, once a desirepressure is reached, the pressure valve 172 on the pressure cap 170 maybe opened to allow the low pressure surface 164 to be exposed to thelower pressure outside of the pressure vessel 150. Accordingly, thecontents of the interior volume 151 including a removal agent 152 woulddiffuse, flow, or otherwise migrate from the elevated pressure remainingin the interior volume 151 through the at least partially connectedinterstitial regions between diamond grains in the at least partiallyleached PCD table 126 to the lower outside environment pressure at thelower pressure surface 164, thereby dissolving, sweeping, and/orotherwise disposing of leaching agents and/or leaching by-products inthe PCD body 124.

In embodiments, the act 338 of exposing the at least partially leachedPCD table 128 to the removal agent may comprise diffusing the removalagent through a PCD body which may further include diffusing the removalagent through a PCD body for different durations. In an embodiment, thepressurized removal agent 152 may diffuse through the PCD body for about24 hours. In an embodiment, the pressurized removal agent 152 maydiffuse or flow through the PCD body for about 20 hours, about 16 hours,about 12 hours, about 8 hours, about 4 hours, or for about 2 hours. Inan embodiment, ranges of cleaning durations may include about 1 hour toabout 24 hours, about 2 hours to about 20 hours, about 4 hours to about16 hours, or about 8 hours to about 12 hours.

It will be readily recognized that depending on many conditionsincluding, but not limited to, the pressure exerted from the interiorvolume 151 including the removal agent 152; the type, composition, andconcentration of the removal agent components; the thickness of the PCDbody, and/or the size and extent of interconnectivity of theinterstitial regions between the bonded diamond grains of the at leastpartially leached PCD table 126; different rates of flow or diffusionthrough the PCD body 120 may be achieved. For example, in an embodiment,the PCD table 124 made using larger diamond particles 104 may havelarger interstitial spaces between bonded diamond grains and may allowfor a faster diffusion or flow of removal agent 152 through saidinterstitial spaces than a PCD table made using smaller diamond grains.Accordingly, in an embodiment, different PCD table manufacturingconditions including but not limited to diamond particle size, HPHTconditions, leaching agent composition, leaching conditions, removalagent composition, and cleaning conditions may be manipulated to effect(i.e., adjust from faster to slower, or vice versa) the rate of flow ofremoval agent through the at least partially leached PCD table 126.

The act 330 of at least partially removing at least one leachingby-product or at least one leaching agent from the at least partiallyleached PCD body 126 may be repeated using the same or different removalagents, the same or different temperatures, the same or differentpressures, the same or different durations, and combinations thereof.

Referring back to FIG. 3A, after the act 330 of removing at least oneleaching by-product or at least one leaching agent from the at leastpartially leached PCD table, the at least partially leached and cleanedPCD table may optionally be infiltrated in act 335 with an infiltrant.Suitable infiltrants may include Group VIII infiltrants such as thosediscussed above; non-Group VIII infiltrants such as by way ofnon-limiting example, boron, copper, gold, silver, aluminum, tin,antimony, silicon, silicone, carbon, titanium, vanadium, chromium,manganese, niobium, technetium, hafnium, tantalum, tungsten, rhenium,magnesium, lithium, zinc, germanium, gallium, antimony, bismuth,gadolinium, thallium, indium, cadmium, combinations of the foregoing; orany other materials configured to provide increased thermal and/ormechanical stability to the at least partially leached and cleaned PCDtable 128. An infiltrant may be provided in the form of a powder, foil,disc, from a substrate 108, or combinations of any of the foregoing. Inan embodiment, the at least partially leached and cleaned PCD body 128may be infiltrated with an infiltrant during a second HPHT process forattaching/bonding the PCD body 128 to a substrate 108 in a mannersubstantially similar to the HPHT processes described above. In anotherembodiment, the at least partially leached and cleaned PCD body 128 maybe infiltrated with infiltrant during a second HPHT process without thepresence of a substrate 108. During an HPHT process, an infiltrant maymelt and sweep into the empty interstitial spaces of an at leastpartially leached and cleaned PCD body 128, from a surface thereof. Inan embodiment, the temperature used in the second HPHT process is belowthat of the HPHT temperature used to form the PCD body 124 as describedabove, but above that of the melting temperature of the infiltrantmaterial. In an embodiment, suitable HPHT infiltration pressures include4 to 8 GPa, and infiltration temperatures include about 500° C. to about1500° C. In an embodiment, a PCD body is infiltrated with an infiltrantby placing the at least partially leached and cleaned PCD body 128 incontact with an infiltrant material and subjecting the PCD body andinfiltrant material to an HPHT process substantially as described above.In an embodiment, a metal foil (e.g., copper) may be placed on the uppersurface of an at least partially leached and cleaned PCD body, whereinduring a second HPHT process, the copper melts and infiltrates into theat least partially empty pores spaces between polycrystalline diamondgrains. In an embodiment, a substrate comprising a metallic infiltrantmay be placed under an at least partially leached and cleaned PCD body128, wherein during a second HPHT process, the metallic infiltrant inthe substrate 108 melts and infiltrates into the at least partiallyempty pores spaces between polycrystalline diamond grains of the PCDbody 128. An infiltrant may be provided in an amount sufficient to, orinfiltrated by conditions suitable to, limit infiltration of theinfiltrant to a specific region of the at least partially leached andcleaned PCD body. For example, an infiltrant provided from the substratemay infiltrate only into the region 132 depicted in FIG. 1F, or aninfiltrant provided at the upper surfaced of the PCD table may beinfiltrated only into region 131 depicted in FIG. 1F. In an embodiment,substantially the entire PCD table may be infiltrated by one or moreinfiltrants. In an embodiment, an at least partially leached and cleanedPCD body 128 is infiltrated from both the upper surface from a powder,foil, or disc, and below the PCD table from the substrate.

Referring back to FIG. 3A, the act 340 of bonding an at least partiallyleached and cleaned PCD body to a substrate includes joining the PCDbody to a substrate in a second HPHT process, substantially similar tothe HPHT process described above. In an embodiment of the act 340, theat least partially leached and cleaned PCD body 128 and substrate 108may be placed in a pressure transmitting medium, such as a refractorymetal can, graphite structure, pyrophyllite or other pressuretransmitting structure, or another suitable container or supportingelement. The pressure transmitting medium, including the assembly, maybe subjected to a second HPHT process using an HPHT press at atemperature of at least about 1000° C. (e.g., about 1300° C. to about1600° C.) and a cell pressure of at least 4 GPa (e.g., about 5 GPa toabout 10 GPa, about 7 GPa to about 9 GPa) for a time sufficient to bondthe at least partially leached and cleaned PCD body 128 to the substrate108 and form a PDC 120′ as shown in FIG. 1F. The HPHT process bonds theat least partially leached and cleaned PCD body/table 128 to thesubstrate 108 and may cause metallic infiltrant from the substrate 108or another source to infiltrate the interstitial regions of the at leastpartially leached and cleaned PCD body/table 128 to produce an at leastpartially leached, cleaned and infiltrated PCD table 130. The HPHTtemperature may be sufficient to melt at least one constituent of thesubstrate 108 (e.g., cobalt, nickel, iron, alloys thereof, or anotherconstituent) that infiltrates the at least partially leached and cleanedPCD body 128. The PDC 120′ so-formed includes an infiltrated PCD body130 in which the interstitial regions thereof are at least partiallyfilled with the metallic infiltrant from the substrate 108 therebyforming an infiltrated region 132 on the infiltrated PCD body 130. In anembodiment, the second infiltrated region 132 may be disposed nearestthe substrate and include metallic infiltrant such cobalt in theinterstitial regions therein. In an embodiment, the first region 131 andthe second infiltrated region 132 may be infiltrated simultaneously withdifferent infiltrants during a second HPHT process wherein an at leastpartially leached and cleaned PCD table 128 is bonded to the substrate108. In an embodiment, a first non-catalyzing infiltrant may bepositioned adjacent to the at least partially leached and cleaned PCDtable 128 opposite the substrate 108, the substrate may comprise a groupVIIIB infiltrant (e.g., cobalt) and be positioned opposite thenon-catalyzing infiltrant wherein both infiltrants infiltrate the atleast partially leached and cleaned PCD table 128 under HPHT conditionsthereby forming the first region 131 and the second infiltrated region132 in the at least partially leached, cleaned and infiltrated PCD table130.

It is noted that the PDC 120′ may exhibit other geometries than thegeometry illustrated in FIG. 1F. For example, the PDC 120′ may exhibit anon-cylindrical geometry. Other HPHT processes, cleaning processes, andresultant PDCs may be formed according to other techniques as disclosedin U.S. patent application Ser. No. 13/027,954 and U.S. Pat. Nos.7,845,438 and 8,236,074, which are incorporated herein, in theirentirety, by this reference.

In an embodiment, the act 340 of bonding the at least partially leachedand cleaned PCD body 128 to the substrate 108 may include brazing the atleast partially leached and cleaned PCD body 128 to the substrate 108.In an embodiment, a braze material configured to bond the at leastpartially leached and cleaned PCD body 128 to the substrate 108 may bedisposed between the PCD body and the substrate and then subjected toHPHT conditions, wherein the brazing material bonds the PCD body to thesubstrate by infiltrating the at least partially leached and cleaned PCDbody 128 and cooling therein.

It is contemplated that the leaching and cleaning techniques andapparatuses described herein may be utilized and or adopted for use witha PDC (i.e., a PCD table still bonded to a substrate). In an embodiment,a PCD table may be bonded to a substrate and portions of the PCD tableand/or substrate may be masked to contain leaching only to desire areasof the PDC. The masked PDC may be leached similarly to the methodsdescribed above. The resulting at least partially leached PDC may beinserted into a pressure vessel suitable for holding a PDC, after whichthe PDC may undergo cleaning substantially as described above with theremoval agent 152 exiting from at least a single side surface of the PCDtable bonded to a substrate. In embodiments, a PCD table on a PDC may befurther leached and or cleaned, according to the methods disclosedherein, after the PCD table has been bonded to the substrate in thesecond HPHT process. For example, leaching and/or cleaning/removing maybe carried out to a desired depth on the PCD table according to themethods described herein.

FIG. 4 is an isometric view and FIG. 5 is a top elevation view of arotary drill bit 400 according to an embodiment. The rotary drill bit400 includes at least one PDC fabricating according to any of thepreviously described PDC embodiments. The rotary drill bit 400 comprisesa bit body 402 that includes radially and longitudinally extendingblades 404 with leading faces 406, and a threaded pin connection 408 forconnecting the bit body 402 to a drilling string. The bit body 402defines a leading end structure configured for drilling into asubterranean formation by rotation about a longitudinal axis 410 andapplication of weight-on-bit. At least one PDC cutting element,manufactured and configured according to any of the previously describedPDC embodiments (e.g., the PDC 120′ shown in FIG. 1F), may be affixed torotary drill bit 400 by, for example, brazing, mechanical affixing, oranother suitable technique. With reference to FIG. 5, each of aplurality of PDCs 412 is secured to the blades 404. For example, eachPDC 412 may include a PCD table 414 bonded to a substrate 416. Moregenerally, the PDCs 412 may comprise any PDC disclosed herein, withoutlimitation. In addition, if desired, in an embodiment, a number of thePDCs 412 may be conventional in construction. Also, circumferentiallyadjacent blades 404 define so-called junk slots 418 therebetween, asknown in the art. Additionally, the rotary drill bit 400 includes aplurality of nozzle cavities 420 for communicating drilling fluid fromthe interior of the rotary drill bit 400 to the PDCs 412.

FIGS. 4 and 5 merely depict one embodiment of a rotary drill bit thatemploys at least one cutting element comprising a PDC fabricated andstructured in accordance with the disclosed embodiments, withoutlimitation. The rotary drill bit 400 is used to represent any number ofearth-boring tools or drilling tools, including, for example, core bits,roller cone bits, fixed cutter bits, eccentric bits, bicenter bits,reamers, reamer wings, mining rotary drill bits, or any other downholetool including PDCs, without limitation.

The PDCs disclosed herein may also be utilized in applications otherthan rotary drill bits. For example, the disclosed PDC embodiments maybe used in thrust-bearing assemblies, radial bearing assemblies,wire-drawing dies, artificial joints, machining elements, PCD windows,and heat sinks.

FIG. 6 is an isometric cut-away view of a thrust-bearing apparatus 600according to an embodiment, which may utilize any of the disclosed PDCembodiments as bearing elements. The thrust-bearing apparatus 600includes respective thrust-bearing assemblies 602. Each thrust-bearingassembly 602 includes an annular support ring 604 that may be fabricatedfrom a material, such as carbon steel, stainless steel, or anothersuitable material. Each support ring 604 includes a plurality ofrecesses (not labeled) that receives a corresponding bearing element606. Each bearing element 606 may be mounted to a corresponding supportring 604 within a corresponding recess by brazing, press-fitting, usingfasteners, combinations thereof, or another suitable mounting technique.One or more, or all of bearing elements 606 may be manufactured andconfigured according to any of the disclosed PDC embodiments. Forexample, each bearing element 606 may include a substrate 608 and a PCDtable 610, with the PCD table 610 including a bearing surface 612.

In use, the bearing surfaces 612 of one of the thrust-bearing assemblies602 bears against the opposing bearing surfaces 612 of the other one ofthe bearing assemblies 602. For example, one of the thrust-bearingassemblies 602 may be operably coupled to a shaft to rotate therewithand may be termed a “rotor.” The other one of the thrust-bearingassemblies 602 may be held stationary and may be termed a “stator.”

FIG. 7 is an isometric cut-away view of a radial bearing apparatus 700according to an embodiment, which may utilize any of the disclosed PDCembodiments as bearing elements. The radial bearing apparatus 700includes an inner race 702 positioned generally within an outer race704. The outer race 704 includes a plurality of bearing elements 706affixed thereto that have respective bearing surfaces 708. The innerrace 702 also includes a plurality of bearing elements 710 affixedthereto that have respective bearing surfaces 712. One or more, or allof the bearing elements 706 and 710 may be configured according to anyof the PDC embodiments disclosed herein. The inner race 702 ispositioned generally within the outer race 704, with the inner race 702and outer race 704 configured so that the bearing surfaces 708 and 712may at least partially contact one another and move relative to eachother as the inner race 702 and outer race 704 rotate relative to eachother during use.

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments are contemplated. The various aspects andembodiments disclosed herein are for purposes of illustration and arenot intended to be limiting. Additionally, the words “including,”“having,” and variants thereof (e.g., “includes” and “has”) as usedherein, including the claims, shall be open ended and have the samemeaning as the word “comprising” and variants thereof (e.g., “comprise”and “comprises”).

The invention claimed is:
 1. A method of cleaning an at least partiallyleached polycrystalline diamond body, the method comprising: positioningthe at least partially leached polycrystalline diamond body within apressure vessel such that at least one surface of the at least partiallyleached polycrystalline diamond body is exposed to an environment insideof the pressure vessel and at least one surface is exposed to anenvironment outside of the pressure vessel; at least partially fillingthe pressure vessel with a removal agent; elevating a pressure of theremoval agent in the pressure vessel relative to an ambient atmosphericpressure of the environment outside of the pressure vessel; and exposingthe at least partially leached polycrystalline diamond body to theremoval agent in the pressure vessel.
 2. The method of claim 1, whereinexposing the at least partially leached polycrystalline diamond body tothe removal agent in the pressure vessel includes diffusing the removalagent through the at least partially leached polycrystalline diamondbody to the environment outside of the pressure vessel.
 3. The method ofclaim 1, wherein positioning the at least partially leachedpolycrystalline diamond body within a pressure vessel includes formingan interior volume within the pressure vessel between at least onesidewall, a back wall, and a surface of the polycrystalline diamondbody.
 4. The method of claim 3, wherein the interior volume includes theremoval agent therein.
 5. The method of claim 1, wherein elevating apressure of a removal agent in the pressure vessel includes heating theremoval agent to create an increased vapor pressure.
 6. The method ofclaim 5, wherein heating the removal agent includes operating a heatingelement located within the pressure vessel.
 7. The method of claim 5,wherein heating the removal agent includes operating a heating systempositioned outside of the pressure vessel including one or more of anoven, kiln, heating element, induction heating system, microwave system,or a salt bath.
 8. The method of claim 1, wherein elevating a pressureof a removal agent in the pressure vessel includes using a pump.
 9. Themethod of claim 1, wherein the removal agent includes one or more of anaqueous component, a supercritical component, a chelating component,inorganic component, or an organic component.
 10. The method of claim 9,wherein the aqueous component includes at least one of sodium hydroxide,potassium hydroxide, lithium hydroxide, hydrochloric acid, nitric acid,hydrofluoric acid, sulfuric acid, or aqua regia.
 11. The method of claim9, wherein the supercritical component includes one or more of water orcarbon dioxide.
 12. The method of claim 9, wherein the chelatingcomponent includes one or more of sodiumbis-(2-ethylhexyl)sulfosuccinate, a fluorinated sodiumbis-(2-ethylhexyl)sulfosuccinate, or a perfluoropolyether phosphate. 13.The method of claim 9, wherein the organic component includes at leastone chemical selected from the group consisting of methane, ethane,propane, ethylene, propylene, methanol, ethanol, acetone, pentane,butane, sulfur hexafluoride, xenon dichlorodifluoromethane,trifluoromethane, isopropanol, nitrous oxide, ammonia, methylamine, anddiethyl ether.
 14. A method of cleaning an at least partially leachedpolycrystalline diamond body, the method comprising: positioning the atleast partially leached polycrystalline diamond body within a pressurevessel such that at least one surface of the at least partially leachedpolycrystalline diamond body is exposed to an environment inside of thepressure vessel and at least one is surface exposed to an environmentoutside of the pressure vessel; at least partially filling the pressurevessel with a removal agent including at least one of a supercriticalcomponent, an aqueous component, a chelating component, or an organiccomponent; elevating a pressure and a temperature of the removal agentin the pressure vessel relative to an ambient atmospheric pressure andtemperature of the environment outside of the pressure vessel to inducea supercritical state in at least one component of the removal agent;and exposing the at least partially leached polycrystalline diamond bodyto the removal agent.
 15. The method of claim 14 wherein exposing the atleast partially leached polycrystalline diamond body to the removalagent includes diffusing the removal agent through the at leastpartially leached polycrystalline diamond body.
 16. The method of claim14, wherein the supercritical component includes one or more of water orcarbon dioxide.
 17. The method of claim 16, wherein the pressure withinthe pressure vessel is more than about 7.3 MPa and the temperaturewithin the pressure vessel is more than about 31° C.
 18. The method ofclaim 16, wherein the pressure within the pressure vessel is more thanabout 22.1 MPa and the temperature within the pressure vessel is morethan about 374° C.
 19. The method of claim 15, wherein the aqueouscomponent includes one or more of sodium hydroxide, potassium hydroxide,lithium hydroxide, hydrochloric acid, nitric acid, hydrofluoric acid,sulfuric acid, phosphoric acid, potassium permanganate, or aqua regia.20. The method of claim 15, wherein the organic component includes oneor more of methane, ethane, propane, ethylene, propylene, methanol,ethanol, acetone, pentane, butane, sulfur hexafluoride, xenondichlorodifluoromethane, trifluoromethane, isopropanol, nitrous oxide,ammonia, methylamine, or diethyl ether.